This invention relates to a multi-sheet glazing unit and, in particular, to a multi-sheet glazing unit having a pair of outer glass sheets separated by and secured to a spacer frame and one or more glass sheet(s) between and spaced from the outer sheets and one another by sheet retaining members, and to a method of making a multi-sheet glazing unit.
European Patent Application Publication Number 0 475 213 A1 published 18.03.92 Bulletin 92/12 (hereinafter xe2x80x9cEP Applicationxe2x80x9d) and U.S. Pat. No. 5,655,282 (hereinafter xe2x80x9cU.S. Pat. No. ""282xe2x80x9d) disclose a thermal insulating glazing unit having three or more sheets with a spacer frame between and adhered to adjacent glass sheets. Although the techniques for making insulating glazing units having three or more sheets disclosed in the EP Application and U.S. Pat. No. ""282 are acceptable, it would be advantageous to provide a multi-sheet glazed unit that does not have a spacer frame between adjacent glass sheets thereby reducing the number of spacer frames required in the fabrication of such units.
U.S. Pat. No. 5,531,047 (hereinafter xe2x80x9cU.S. Pat. No. ""047xe2x80x9d) discloses multi-sheet glazing units having one or more inner glass sheets spaced from and between a pair of outer glass sheets. In general, the outer glass sheets are separated by and secured to a spacer frame having a U-shaped cross section. On the base of the spacer frame between the outer legs is a layer of a pliable material having one or more groove(s) for receiving edge portions of the inner glass sheet(s). The unit of U.S. Pat. No. ""047 is fabricated by wrapping spacer stock around the inner sheet(s) while positioning the edge portions of the inner sheet(s) in the groove(s) of the pliable material to position the inner sheet(s) within the spacer frame. After the inner sheet(s) is(are) within the spacer frame, the outer sheets are secured to the outer surfaces of the spacer frame by a moisture-impervious sealant. Although the techniques disclosed in U.S. Pat. No. ""047 are acceptable, there are limitations. For example, positioning the spacer stock around the inner sheet(s) may disturb the pliable material on the base of the spacer frame, making the unit unsightly. Further mounting the intermediate sheet(s) in the pliable material on the base of the spacer stock requires time and mounting precision.
U.S. Pat. No. 5,644,894 (hereinafter xe2x80x9cU.S. Pat. No. ""894xe2x80x9d)discloses multi-sheet glazing units having one or more inner glass sheet(s) mounted within a U-shaped spacer frame and outer sheets adhered to outer surfaces of the spacer frame by a moisture-impervious sealant. The intermediate sheet(s) is(are) held in position by spaced rows of raised portions formed in the base of the spacer frame. Although the glazing units disclosed in U.S. Pat. No. ""894 are acceptable, there are limitations. More particularly, providing spaced rows of raised portions in the base of the spacer frame requires an extra step in the process of making the spacer frame.
U.S. Pat. No. 5,553,440 (hereinafter xe2x80x9cU.S. Pat. No. ""440xe2x80x9d) also discloses multi-sheet glazing units having three or more glass sheets. In general, the units include a pair of outer glass sheets separated by and adhered to outer opposed surfaces of a spacer frame having a U-shaped cross-section. A sheet retaining member mounted between the upright legs of the spacer frame has one or more groove(s) for receiving marginal and peripheral edge portions of one or more inner sheet(s). Although the glazing units taught in U.S. Pat. No. ""440 are acceptable, there are limitations. More particularly, wrapping the spacer stock around the inner sheet(s) while positioning the edge of the inner sheet(s) in the groove(s) of the sheet retaining members requires assembly time and precision.
United States Statutory Invention Regulation No. H975 (hereinafter xe2x80x9cPublication H975xe2x80x9d), published Nov. 5, 1991, discloses a multi-sheet unit having a pair of outer sheets spaced from one another by and secured to a spacer frame. An example of Publication H975 discloses the construction of the unit by mounting the edge supports on the edge portions of an inner sheet and setting the inner sheet having the edge supports within the closed spacer frame. Thereafter, the edge supports are secured to the frame. As can be appreciated, mounting edge supports on the edges of an inner sheet and thereafter, securing the edge supports to the spacer frame is time consuming.
As can now be appreciated, it would be advantageous to provide multi-sheet glazing units, i.e., glazing units having three or more sheets, and methods of making same that do not have the limitations of presently available multi-sheet glazing units and methods of making same.
This invention relates to a sheet retaining member having a sheet engaging member having a vertical stop and a horizontal support and a securing or locking member securable on the horizontal support spaced from the vertical stop to form a groove for receiving edge portion of a sheet e.g. glass sheet.
This invention also relates to multi-sheet glazing units, i.e., a glazing unit having three or more sheets. The multi-sheet unit includes a spacer frame having opposed legs and a base connected to one another to have a generally U-shape. A sheet is mounted on outer surface of each of the legs of the spacer frame, e.g., by a moisture-impervious sealant. A support facility is mounted on the spacer frame spaced from the base and between the sheets. A sheet engaging member is mounted on the support facility between the sheets to provide a sheet retaining member, and the sheet retaining member has a groove facing the interior of the spacer frame. The groove is formed by a wall defined as a first wall lying in a plane intersecting the base of the spacer frame and a securing or locking member secured to the sheet engaging member. The securing member having a wall defined as a second wall lying in a plane intersecting the base of the spacer frame. The first and second walls are spaced from one another to provide the walls of the groove of the sheet engaging member. A third or inner sheet is mounted in the groove.
The invention further relates to a method of making a multi-sheet glazing unit. The method includes, among other steps, the following steps. A spacer and a plurality of sheet retaining members are provided. At least one of the sheet retaining members has a vertical portion and a non-vertical portion to provide an edge stop, and has a securing or locking member. The sheet retaining members are mounted on the spacer frame spaced from one another with the edge stop facing the interior of the spacer frame. Edge portions of the sheet are biased against the edge stop afterwhich the securing member is secured to the non-vertical portion. An outer sheet is secured on each side of opposed sides of the spacer frame to provide the multi-sheet unit having outer sheets and inner sheet(s) spaced from one another.